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Relatively few catalytic systems are able to control the stereochemistry of electronically excited organic intermediates. Here we report the discovery that a chiral Lewis acid complex can catalyze triplet energy transfer from an electronically excited photosensitizer. We applied this strategy to asymmetric [2 + 2] photocycloadditions of 2'-hydroxychalcones, using tris(bipyridyl) ruthenium(ll) as a sensitizer. A variety of electrochemical, computational, and spectroscopic data rule out substrate activation by means of photoinduced electron transfer and instead support a mechanism in which Lewis acid coordination dramatically lowers the triplet energy of the chalcone substrate. We expect that this approach will enable chemists to more broadly apply their detailed understanding of chiral Lewis acid catalysis to stereocontrol in reactions involving electronically excited states.

Spending time in nature is known to benefit human health and well-being, but evidence is mixed as to whether biodiversity or perceptions of biodiversity contribute to these benefits. Perhaps more importantly, little is known about the sensory modalities by which humans perceive biodiversity and obtain benefits from their interactions with nature. Here, we used a ‘phantom birdsong chorus' consisting of hidden speakers to experimentally increase audible birdsong biodiversity during ‘on' and ‘off' (i.e. ambient conditions) blocks on two trails to study the role of audition in biodiversity perception and self-reported well-being among hikers. Hikers exposed to the phantom chorus reported higher levels of restorative effects compared to those that experienced ambient conditions on both trails; however, increased restorative effects were directly linked to the phantom chorus on one trail and indirectly linked to the phantom chorus on the other trail through perceptions of avian biodiversity. Our findings add to a growing body of evidence linking mental health to nature experiences and suggest that audition is an important modality by which natural environments confer restorative effects. Finally, our results suggest that maintaining or improving natural soundscapes within protected areas may be an important component to maximizing human experiences.

Visitation to parks and protected areas is a common COVID-19 coping strategy promoted by state and national public health officials and political leadership. Crowding and congestions in parks has been a perennial problem and the ability to socially distance within them is an unproven assumption. Is it possible to socially distance in a busy national park that has been designed to concentrate use? An observational study was conducted in July 2020 at the outside foyer of the Visitor Center of Arches National Park. Motion sensor cameras were placed to record one-minute videos when a person entered the field of view. Number of groups, group size, facial coverings and encounters within 6 feet (1.83 meters) of other groups were recorded. Groups were smaller on average than recorded in previous studies. Approximately 61% of the visitors wore masks. Most groups (69%) were able to experience the visitor center with no intergroup encounters. We model the probability of intergroup encounters and find as group size and number of groups increases, the probability of encounters rises. With four groups present, the probability of one or more encounters ranges from 19% to 40% for common group sizes, while if eight groups are present, the probability of one or more encounters increases from 34% to 64% for common group sizes. Under conditions in which park visitors have the physical space to avoid close encounters with other groups they are taking advantage of the opportunity. Visitors are minimizing group size, wearing masks, and remaining socially distant. However, encounters increase as the number or the size of the groups increases. In other areas of the parks this ability to avoid encounters may not be as possible. We recommend that park managers continue to appeal for compliance with CDC guidelines, especially the wearing of masks and encouraging visitors to split up into small groups when visiting.

Researchers continue to explore ways to understand and promote pro-environmental behavior (PEB) amongst various populations. Despite this shared goal, much debate exists on the operationalization and the dimensionality of PEB and how it is measured. This piecemeal approach to measurement has limited the ability to draw conclusions across studies. We address limitations associated with previous measures of PEB by developing a multi-dimensional scale that is validated across both a general population of individuals residing in the United States as well as a group of individuals associated with a pro-environmental organization. Exploratory and confirmatory factor analyses and reliability estimation were conducted for the developed measure across these two populations. Measurement invariance testing was also utilized to assess the psychometric stability of the scale across the two groups. Results indicated an 11 item scale was best fitting with two sub-scales: private and public behaviors. Implications for research and practice are discussed.

This research empirically merges together two related theories: the elaboration likelihood model and the theory of planned behavior. A structural equation modeling approach is used to evaluate the relationship between the two theories and their collective impacts on behavioral intentions. The results suggest elaboration predicts the components of the theory of planned behavior (attitudes, subjective norms, and perceived behavior control), which in turn all predicted behavior intentions. Furthermore, results showed that the components of the theory of planned behavior partially meditated the relationship between elaboration and behavioral intentions, indicating that elaboration works mostly through the components of the theory of planned behavior to impact behavioral intentions. This study represents an improved understanding of the influence of communication techniques on visitor behaviors in sustainable tourism settings. Additionally, the discussion exemplifies how these techniques can be used to improve communications and evaluate communication strategies.

Visitors to Colter Bay Village in Grand Teton National Park were surveyed to elicit their evaluations of experimental outdoor lighting conditions. Luminaires capable of dimming and switching between two LED modules (white, blended red-white) were installed in street and parking areas. The blended red-white lamps consisted of 30 narrowband LED with a peak wavelength 623 nm and two 3000 K white LEDs. Similar “red” lamps were previously shown to reduce impacts to bats and insects. The white and red lamps were closely matched for luminance. Measured horizontal illuminance at survey locations had an interquartile range from 0.63 to 3.82 lx. The red lamps produced lower perceived brightness ( V B 2 ( λ )), even after reflection off asphalt, yet survey participants expressed higher ratings for visual comfort and safety under red lighting. Surveys conducted earlier in the evening, with higher levels of predicted solar and measured horizontal illuminance, rated higher on visual comfort and safety, though these correlations were not as strong as the effect of lamp color. Streetlight ratings and support for lighting that protected natural resources were not contingent upon age or gender. Survey participants assessed red lighting as more protective of the environment. These results demonstrate that outdoor lighting designed to reduce ecological impacts can yield superior nocturnal experience for pedestrians.

Burgeoning urbanization, development and human activities have led to reduced opportunities for nature experience in quiet acoustic environments. Increasing noise affects both humans and wildlife alike. We experimentally altered human‐caused sound levels in a paired study using informational signs that encouraged quiet behaviours in week‐on, week‐off blocks on the trail system of Muir Woods National Monument, California, USA to test if the soundscape influences both wildlife and human experiences. Using continuous measurements from acoustic recording units (n = 13) spatially distributed within the park, we found signs significantly lowered sound levels by approximately 1.2 decibels (A‐weighted), thereby increasing listening area by 24% and bird availability by approximately 5.8% for every 1 decibel decrease. Visitor‐intercept surveys (n = 537) revealed that our mitigation increased the number of birds perceived by visitors, rankings of soundscape pleasantness, and importantly, preferences for soundscape management. By lowering human‐caused sound levels, we created an acoustic environment equivalent to a ~21% reduction in visitors. The positive feedback cycle we describe may lead to increased conservation support in a time when the extinction of nature experience looms. A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.

Outdoor recreationists represent a key population to educate for pro-environmental behavior (PEB). Given that previous research has found a mixed relationship between outdoor recreation and PEB, this research merges several concepts to better understand the social psychological nuances of this relationship. Specifically, this study explores how specialization regarding environmentally responsible outdoor recreation is related to other PEBs through a behavioral spillover framework. A correlational structural equation model was utilized to test this framework within a merged population of individuals from the Leave No Trace organization and general United States citizens. The results suggested that traditional behavioral spillover dynamics held for private PEBs but not public PEBs. However, recreation specialization was significantly related to both PEB types. These results suggest that the current behavioral spillover theory may only explain the relationship between some PEBs. Furthermore, environmentally responsible outdoor recreation specialization may be a promising pathway toward a spillover into encouraging private and public PEBs.

Class III peroxidases are members of a large plant-specific sequence-heterogeneous protein family. Several sequence-conserved homologs have been associated with lignin polymerization in Arabidopsis thaliana , Oryza sativa , Nicotiana tabacum , Zinnia elegans , Picea abies , and Pinus sylvestris . In Populus trichocarpa , a model species for studies of wood formation, the peroxidases involved in lignin biosynthesis have not yet been identified. To do this, we retrieved sequences of all PtrPOs from Peroxibase and conducted RNA-seq to identify candidates. Transcripts from 42 PtrPOs were detected in stem differentiating xylem (SDX) and four of them are the most xylem-abundant (PtrPO12, PtrPO21, PtrPO42, and PtrPO64). PtrPO21 shows xylem-specific expression similar to that of genes encoding the monolignol biosynthetic enzymes. Using protein cleavage-isotope dilution mass spectrometry, PtrPO21 is detected only in the cell wall fraction and not in the soluble fraction. Downregulated transgenics of PtrPO21 have a lignin reduction of ~20 % with subunit composition (S/G ratio) similar to wild type. The transgenics show a growth reduction and reddish color of stem wood. The modulus of elasticity (MOE) of the stems of the downregulated PtrPO21-line 8 can be reduced to ~60 % of wild type. Differentially expressed gene (DEG) analysis of PtrPO21 downregulated transgenics identified a significant overexpression of PtPrx35, suggesting a compensatory effect within the peroxidase family. No significant changes in the expression of the 49 P. trichocarpa laccases (PtrLACs) were observed.

Over the past decade, many national park units in the United States broke visitation records. Arches National Park (UT, USA) is no exception. Between 2011 and 2021, visitation increased 74%. As part of considering management options to address the issues from sustained and concentrated visitation, Arches implemented a pilot timed entry system from 3 April to 3 October 2022. This article compares visitor perceptions, characteristics, and support for management actions before and during the pilot timed entry system using data from visitor intercept surveys. Findings suggest visitors experience quality improved across the park and on hiking trails during the pilot timed entry system. Visitor characteristics were extremely similar, and there were no differences in local residency, group size, vehicle occupancy, race, ethnicity, first time visitation, education level, or household income. Visitors were more likely to plan for the trip further in advance and were less likely to re-enter the park during the pilot timed entry system. Lastly, visitors demonstrated more support for timed entry and lower levels of support for expanding parking, site specific reservations, and temporary closures during the pilot timed entry system. These results reflect unique insights for managers considering managed access systems like timed entry to sustainably manage visitor use in parks and protected areas.